Liquid-immersed electrical device



Filed March 11, 1957 FIGI.

2 Sheets-Sheet 1 Nov. 27, 1962 c. G. DUENKE LIQUID-IMMERSED ELECTRICALDEVICE 2 Sheets-Sheet 2 Filed March 11, 1957 F'IG.4.

United States Patent Ofilice 3,056,207 Patented Nov. 27, 1962 3.066,207LIQUID-IMMERSED ELECTRICAL DEVICE Clarence G. Duenke, Webster Groves,Mo., assignor to Moloney Electric Company, St. Louis, Mo., 2 corporationof Delaware Filed Mar. 11, 1957, Ser. No. 645,192 4 Claims. (Cl. 200150)This invention relates to liquid-immersed electrical devices, such asoil-immersed step voltage regulators and oil-immersed circuit breakers,and more particularly to untanking means for such devices.

Liquid-immersed electrical devices of the class described conventionallycomprise a tank containing a liquid such as oil and an electrical unitimmersed in the liquid in the tank. For conveniently servicing such adevice, the electrical unit must be raised relative to the tank, thisoperation being known as untanking. Among the several objects of thisinvention may be noted the provision of such a device with power meansfor effecting untanking, wherein the power means is of the hydraulictype and utilizes liquid from the tank as hydraulic fluid; the provisionof such a device with power means incorporated in the tank and utilizingcertain components of the power means for supporting the electricalunit; and thelprovision of such a device with power means as describedwhich is of economical construction and easy to use. Other objects andfeatures will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the constructions hereinafterdescribed, the scope of the invention being indicated in the followingclaims.

In the accompanying drawings, in which several of various possibleembodiments of the invention are illustrated,

FIG. 1 is a vertical section of a step voltage regulator embodying theinvention, showing the electrical unit of the regulator untanked;

FIG. 2 is a vertical section at right angles to the FIG. 1 sectionshowing the electrical unit in its lowered position in the tank;

FIG. 3 is a horizontal section taken on line 33 of FIG. 1; and,

FIG. 4 is a vertical section illustrating a circuit breaker embodyingthe invention.

Corresponding reference characters indicate correspondingpartsthroughout the several views of the drawings.

Referring to the drawings, FIGS. 13 illustrate the invention as it isapplied to an oil-immersed pole type step voltage regulator such as isused outdoors in an electric power distribution system. As shown, thisdevice comprises a tank 1 which is filled with oil to a level such asindicated at L. A cover for the tank is indicated at 3. It will beunderstood that the tank 1 is secured to a concrete pad, or mounted inany other conventional manner. Extending down from the cover at oppositesides thereof are two long cylinders 5. Each of these may consist simplyof a length of pipe. The upper ends of these cylinders are secured as bywelding to the cover and are closed. The cylinders are open at theirlower ends. The cylinders 5 serve as supporting means for an electricalunit, generally designated 7, shown to comprise a main transformer 9, acurrent transformer 11, a switching reactor 13, a switch mechanism 15and an electric motor drive 17 for the switch mechanism. The maintransformer 9 is supported by a platform 19 extending between thecylinders 5 at their lower ends. The current transformer and switchingreactor are supported by a platform 21 extending between the cylinders 5above the main transformer 9. The switch mechanism 15 is mounted on aplatform 23 extending between the cylinders 5 above the currenttransformer and the switching reactor.

A U-shaped length of pipe, designated in its entirety by the referencecharacter 25, is mounted in the tank 1. The vertical portions or legs ofthe U-shaped pipe are each designated 27, and the base or connectingportion of the U-shaped pipe is designated 29. The base portion 29 isshown as being secured as by welding to an angle iron 31 at the bottomof the tank. The vertical legs 27 of the U-shaped pipe extend up fromthe bottom adjacent the cylindrical wall of the tank. The cylinders 5are telescopically slidable on the legs 27. Packing 33 may be providedat the upper ends of legs 27 for insuring a liquidtight seal between thecylinders 5 and the legs 27. The cylinders 5 and legs or tubes 27constitute a hydraulic lift for the cover 3 and the unit 7. Thecylinders 5 are vertically slidable in guides 35 at the top of the tank.

At the bottom of the tank is a drain hole 39. A drain valve 41 isthreaded in this hole on the outside of the tank. A pipe 43 extends intothe tank from the outside and is connected at 45 to the base portion 29of the U-shaped pipe. On the outer end of pipe 43 is a shutoff valve 47.A manually operable pump is indicated at 49. A conduit 51 (shown as ahose) connects the drain valve and the pump inlet 53. A conduit 55(shown as a hose) connects the pump outlet 57 to the valve 47. A by-passconduit 59 including a shut-off valve 61 is connected between the pumpinlet and outlet.

FIG. 2 shows the unit 7 in lowered position for immersion in the oil inthe tank, the cover 3 engaging the top of the tank. Suitable clamps (notshown) are provided for locking the cover to the tank. To untank theunit 7, the cover clamps are released, valves 41 and 47 are opened,by-pass valve 61 is closed, and the pump is operated to pump oil fromthe tank through conduit 55, valve 47 and pipe 43 to the base portion 29of the U-shaped pipe 25, and thence up through the vertical legs 27 ofthe pipe to the cylinders 5. This raises the cylinders 5, cover 3 andunit 7. To lower the unit 7, the by-pass valve 61 is opened and theweight of unit 7 brings it back down, oil from the cylinders 5 flowingback into the tank through the legs 27, the base portion 29, pipe 43,valve 47, conduit 55, by-pass 59, conduit 51 and the drain valve 41.

It will be understood that the pump 49 may be permanently connected tothe lift constituted by the pipe 25 and the cylinders 5, or it may beonly temporarily connected when needed, the serviceman carrying the pumpwith him for use on diiferent devices to be serviced. In the lattercase, it is a simple matter to connect conduits 51 and 55 to valves 41and 47 and to disconnect the conduits when servicing is completed,valves 41 and 47 being closed before disconnection so that no oil islost from the tank.

FIG. 4 illustrates the invention applied to an oilimmersed circuitbreaker. As shown, this device comprises a frame 60 to which is fixed acover 63 for a tank 65. This tank is filled with oil to a level such asin dicated at L. Adjacent to its upper end the tank has outwardlyextending lugs 67. Fixed in these lugs and extending downward therefromare vertical cylinders 69. Piston rods 71 are fixed to the frame 60 attheir upper ends and extend down into the cylinders 69. Piston rods 71have pistons 73 at their lower ends. The cylinders, piston rods andpistons constitute a hydraulic lift for the tank. Suspended from thecover 63 is an electrical unit generally designated 75. While thedetails of this unit are not material so far as the invention isconcerned, it may be mentioned that it includes blades 77 which areupwardly movable from the position shown in FIG. 4 into contact withstationary contact aoeaaov fingers contained within de-ionizing grids79. nism for moving the blades is indicated at 81.

At the bottom of the tank is a drain hole 83 in which. is threaded adrain valve 85. A manually operable pump 49 is again used, having theby-pass conduit 59 including the shut-ofi valve 61. A flexible hose line87 connects the drain valve 85 and the pump inlet 53. A flexible hoseline 89 leads from the pump outlet 57 to a T M, from which hose lines 95lead to fittings 95 connected into the upper ends of the cylinders 69.

The tank 65 is held in the raised position shown in FIG. 4 by means ofbolts 97 extending down from the cover. In this raised position of thetank, the electrical unit 75 is immersed in the oil in the tank. Tuntank the unit 75, the bolts 97 are released, the drain valve 85 isopened, and the by-pass valve 61 is opened, thereby regulating the rateof descent of the tank. The weight of the tank causes it to slide down,the oil from within the cylinders 69 feeding out of the cylindersthrough fittings 95, hose lines 93, T 91, hose line 89, by-pass 59 andline 87 to the tank 65. This separates the unit 75 from the tank forservicing. To raise the tank, the by-pass valve 61 is closed, then thepump 49 is operated to pump oil from the tank through hose line 89, T 91and hose lines 93 to the cylinders 69. This raises the cylinders 69 andthe tank back up to the FIG. 4 position.

in view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above constructions Withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim:

1. In a liquid-immersed electrical device of the type Mechacomprising atank containing a liquid such as oil and an electrical unit immersed inthe liquid in the tank, the tank and unit being vertically separable forun-\ tanking the unit, means for effecting relative vertical movement ofthe tank and the electrical unit comprising a hydraulic lift located inthe tank, a pump for supplying the lift with liquid under pressure, thepump having an inlet and an outlet, the tank having a drain, a conduitconnecting the drain and the pump inlet, and a conduit connecting thepump outlet to the lift, whereby the tank liquid is utilized ashydraulic fluid for operating the lift.

2. In a liquid-immersed electrical device as set forth in claim 1, thetank being fixed, and the lift being arranged to raise the unit out ofthe tank.

3. In a liquid-immersed electrical device as set forth in claim 2, thelift being located in the tank, part of the lift constituting a supportfor parts of the electrical unit.

4. In a liquid-immersed electrical device as set forth in claim 1, theunit being fixed, and the lift being arranged to allow the tank to belowered from the unit and to raise the tank.

References Cited in the file of this patent UNITED STATES PATENTS CanadaMay 23, 1950

